Session: Presidential Symposium: Plastics and the Oceans: Chemistry for the Journey Ahead:

Plastic pollution is one of the fastest-growing and most widespread environmental problems facing the world today. Recycling and reusing plastic is a solution, but long-term, effective recycling methods remain under development. Plastic pyrolysis is a recycling technique that converts plastics, like polyolefins, back to their constituent monomers. However, fundamental information is not known about this process including the reaction pathways and associated kinetics. In order to gather this information, this study designed, constructed, and evaluated a modified Pulse Heated Analysis of Solid Reactions (PHASR) system to investigate the effects of reaction temperatures (500 to 700 °C) and optimum conditions for analytical techniques. In addition, a Visual PHASR system was created to facilitate high speed photography and visualization of real-time LDPE pyrolysis. Experimental results demonstrated that this new PHASR system has the capability to measure the millisecond resolved evolution of LDPE plastic during this process while yielding pyrolysis products at a constant temperature. The PHASR system demonstrated its ability to deliver a rapid, predictable heating time (20 ms) and cooling time (130–150 ms) while sustaining a stable temperature throughout the reaction. This technique can be broadly used to study the reaction kinetics and chemistry of polymer pyrolysis and many other waste plastic materials.

Matthew Neurock

University of Virginia

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